from .img import find_shapes, write_debug_image
from .pdf import parse_pdf
from .utils import overlaps


def find_marked_products(pdf, workdir, debug=0):
    """Main entry point.  Give a pdf, get matches."""
    (prods, scribbles) = parse_pdf(pdf, workdir, debug)

    if not prods or len(prods) < 1:
        print('no product placement markers found')
        return None

    find_scribbles_shapes(scribbles)
    matches = find_matches(prods, scribbles, 0.10)

    for s in scribbles:
        write_debug_image(workdir, s['page'], prods, scribbles)

    return matches


def find_scribbles_shapes(scribbles):
    for scribble in scribbles:
        imgw, imgh, shapes = find_shapes(scribble['image'])
        rects = [transform(scribble['rect'], imgw, imgh, s) for s in shapes]
        scribble['bboxes'] = rects


def transform(pdf_rect, imgw, imgh, shape):
    """Convert scribble from image coords to pdf coords"""
    # get scale factor for image coords
    # to convert to pdf coordinates
    pdfw = pdf_rect.right - pdf_rect.left
    pdfh = pdf_rect.bottom - pdf_rect.top
    scalew = pdfw / imgw
    scaleh = pdfh / imgh
    return shape.scale(scalew, scaleh).translate(pdf_rect.left, pdf_rect.top)


def find_matches(all_prods, scribbles, overlap_threshold):
    # segment by page
    page_prods = {}
    for p in all_prods:
        pagenum = p['page']
        if pagenum in page_prods:
            page_prods[pagenum].append(p)
        else:
            page_prods[pagenum] = [p]

    matches = []
    for s in scribbles:
        pagenum = s['page']
        if not pagenum in page_prods: continue
        prods = page_prods[pagenum]
        for p in prods:
            for box in s['bboxes']:
                if overlaps(p['rect'], box, overlap_threshold):
                    p['matched'] = s
                    matches.append(p)

    return matches